Search Results (2,039)

Arginase 1 (ARG1) deficiency (ARG1-D) is a rare genetic disorder due to loss of ARG1, the final enzyme in the urea cycle. ARG1-D hepatocytes are impaired in converting arginine into urea, resulting in elevated peripheral arginine and ammonia, which leads to progressive neurological symptoms. Current therapeutic strategies mainly focus on managing plasma arginine and ammonia level, but long-term outcomes remain poor. While no approved treatment specific for ARG1-D is available in the United States, a recombinant protein-based enzyme replacement therapy is available in Europe. Recently, extracellular vesicles (EVs) are emerging as a powerful therapeutic vehicle. By using Capricor’s StealthX^TM platform, EVs were engineered to express human ARG1 on their surface or encapsulated within. Regardless of their localization on the EV membrane, nanograms of ARG1 carried by EVs were biologically active and able to convert arginine into urea as potent as micrograms of human recombinant ARG1 (rHuArg1). Furthermore, ARG1-encapsulating EVs (STX-Arg1-in) were able to deliver ARG1 intracellularly but not EVs carrying ARG1 on their surface or rHuArg1. STX-Arg1-in EVs were further evaluated in a series of in vivo studies, and the results showed that STX-Arg1-in EVs were non-toxic and able to restore arginase activities in the liver of Arg1^−/− mice, which led to a lowered plasma arginine concentration similar to that in wild-type mice. Most importantly, Arg1-in EVs expanded the lifespan of the lethal neonatal Arg1 deficiency mouse model. Taken together, our data suggested StealthX^TM-engineered STX-Arg1-in EVs have a better safety profile due to the extremely low dosage and have great potential as a novel enzyme replacement strategy for patients suffering from ARG1-D. Significance statement: Intracellular delivery of recombinant protein and improved llifespanare endpoints of successful enzyme replacement therapy for the treatment of ARG1-D. Using the StealthX platform, a fully functional ARG1 enzyme was engineered to be carried inside of the extracellular vesicles, which allowed for the intracellular delivery of ARG1 protein in vitro and in vivo, with an improvement of lifespan in a lethal neonatal mouse model of Arg1 deficiency. More importantly, no toxicity was observed, and efficacy was achieved with a low dose, setting the base for an improved therapeutic approach. Full article

Overexpression of protein arginine methyltransferase 5 (PRMT5) is pivotal in MYC-driven primary medulloblastoma tumors, suggesting PRMT5 as a potential therapeutic target. JNJ, a potent PRMT5 inhibitor currently in clinical trials, notably for non-Hodgkin lymphoma and lung cancer, was evaluated in this study. We report a validated LC–MS/MS bioanalytical method for quantifying JNJ in plasma and tissue matrices. The method demonstrated acceptable sensitivity, selectivity, and robustness in accordance with regulatory guidelines. The assay was linear over the range 0.2–500 ng mL⁻¹ (r² = 0.99), with plasma recovery exceeding 84% using only 100 µL of sample. Precision (%RSD < 15%) and accuracy (~91–108%) were within acceptable limits. JNJ showed >94% plasma protein binding and moderate Caco-2 permeability (3.4 ± 0.4 × 10⁻⁶ cm s⁻¹). Hepatic intrinsic clearance was higher in mouse liver microsomes than in human (41 ± 19 vs. 7 ± 0.6 mL min⁻¹ kg⁻¹). Following oral dosing in mice (10 mg kg⁻¹), T_max was 30 min with a C_max of 2781 ± 1033 ng mL⁻¹. Oral bioavailability was low (15%). The validated method was successfully applied to in vitro and in vivo studies and will guide dosing in animal models of medulloblastoma. Full article

RNA degradation plays a vital role in post-transcriptional regulation of gene expression. RNA stability is changed in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD), but its role and underlying mechanisms in sleeve gastrectomy (SG) effectively remodeling hepatocytes and improving MASLD is unclear. A high-fat diet-induced MASLD model for SG and a hepatocyte-specific Zfp36 knockdown mouse model were established to evaluate the role of zinc finger protein 36 (ZFP36) in MASLD. The expression of ZFP36 and TEA domain transcription factor 4 (TEAD4) was examined in liver tissue samples from MASLD patients. Hepatic ZFP36 expression is downregulated in MASLD but is restored following SG. Hepatocyte-specific Zfp36 knockdown exacerbates high-fat diet-induced liver injury and impairs the therapeutic effect of SG on hepatic steatosis. Mechanistically, ZFP36 binds to TEAD4 mRNA to promote its degradation, thereby modulating the Hippo pathway. Inhibition of TEAD4 transcriptional activity reverses the aggravated MASLD phenotype caused by Zfp36 knockdown. In liver biopsy samples from MASLD patients, ZFP36 expression correlates negatively with TEAD4 expression. Collectively, these findings identify SG-induced upregulation of ZFP36 as a critical mechanism for alleviating MASLD through suppression of TEAD4. Full article

Metabolic-dysfunction-associated steatotic liver disease (MASLD) is a major chronic liver disorder that progresses through inflammation and fibrosis to cirrhosis, yet no effective pharmacological therapy is available. Extracellular vesicles (EVs), which are key mediators of intercellular communication, have recently been reported to exert preventative and therapeutic effects in disease models. This study evaluated the oral efficacy of EVs derived from the microalga Chlorella vulgaris (CEVs) in an MASLD mouse model. Male C57BL/6J mice were assigned to a control group (normal diet), an MASLD group (choline- and methionine-deficient high-fat diet; CDHF), or CEV group (CDHF + CEVs). Twelve-week CEV administration did not alter the CDHF-induced reduction in circulating lipid levels or produce an increase in hepatic lipid content. However, CEV treatment significantly suppressed CDHF-induced fibrosis with collagen accumulation and reduced the mRNA expression of fibrosis-related genes, including Col1a1, Acta2, Mmp2, and Timp1. CEVs also significantly downregulated the expression of macrophage-derived inflammatory mediators—Ccl2, Ccr2, Il6 and Il1b—and reduced lobular inflammatory foci. These findings suggest that CEVs attenuate hepatic fibrosis by modulating early inflammation associated with steatosis and inhibiting hepatic stellate cell activation. This study supports the potential of CEVs as a novel oral intervention for slowing MASLD progression. Full article

The emergence of antibiotic resistance in pathogens, including Salmonella typhimurium, poses a major challenge to animal health and safety. Andrographolide is well known for its antibacterial properties and therefore offers potential as an antimicrobial treatment to lessen the damage caused by Salmonella. PANoptosis is defined as an inflammatory coordinated cell death pathway encompassing apoptosis, pyroptosis, and necroptosis. To reduce the organ and tissue damage caused by bacterial infection and reduce antibiotic resistance, this study investigated the effect of andrographolide on liver damage in Salmonella-infected mice. We used a mouse model infected with Salmonella typhimurium for in vivo experiments, which involved the detection of the bacterial load in the liver, liver injury indicators, and expression of related PANoptosis-related genes and proteins. Here, our finding indicated that andrographolide effectively inhibited markers associated with apoptosis, pyroptosis, and necroptosis in mouse hepatocytes, alleviated liver injury and clinical symptoms caused by Salmonella typhimurium in mice, and thus exerted therapeutic effects. In this study, we observed that andrographolide modulated the markers associated with these three pathways, indicating their involvement in PANoptosis. These results suggest that andrographolide significantly relieve Salmonella-induced liver injury by inhibiting PANoptosis, highlighting the potential significance of andrographolide as an effective drug for the treatment of Salmonella. Full article

Lycium barbarum–Polygonatum cyrtonema composite jiaosu (LBPCJ) was prepared by sequential dual-species fermentation and evaluated in a mouse model of alcohol-induced liver injury. Following process optimization, a yeast-first sequential strategy with intermediate pasteurization was selected, comprising an initial Saccharomyces cerevisiae fermentation step, intermediate pasteurization, and a subsequent Lactiplantibacillus plantarum fermentation step. Fermentation reduced pH from 4.68 to 3.51 and increased total acidity from 61.06 to 135.39 g LA/L and total phenolic content from 3.01 to 9.39 mg GAE/mL. In vitro antioxidant-related activities were also higher after fermentation, with DPPH, ABTS, and •OH scavenging rates increasing by 39.90%, 29.78%, and 11.10%, respectively. In mice, LBPCJ administration was associated with lower liver index and serum aminotransferase levels, together with attenuated hepatic histopathological alterations, with the high-dose group (15 mL/kg BW) showing the clearest response. These changes were accompanied by higher hepatic SOD and GSH levels and lower MDA, TNF-α, IL-1β, and IL-6 levels. LBJ and PCJ also improved several measured indicators, while LBPCJ showed changes across multiple endpoints under the tested conditions. Overall, sequential fermentation markedly altered the physicochemical and antioxidant-related properties of LBPCJ, and LBPCJ administration improved multiple indicators related to alcohol-induced liver injury in mice, although the specific constituents and underlying mechanisms remain to be clarified. Full article

Betaine-homocysteine methyltransferase (BHMT) is an enzyme involved in one-carbon metabolism and plays a crucial role in maintaining liver health. In this study, we investigated the impact of liver-specific deletion of BHMT on liver dysfunction using a mouse model. We generated BHMT floxed mice and bred them with albumin Cre to generate liver-specific BHMT knockout (BHMT LKO) mice. Liver tissues harvested from six-month-old chow-fed BHMT floxed and LKO mice were characterized through histological, biochemical, and molecular analyses. BHMT LKO mice displayed a complete loss of hepatic expression of BHMT mRNA, protein and enzyme activity. Histopathological analysis revealed the development of hepatic steatosis in BHMT LKO mice compared to the floxed mice. These morphological changes were supported by biochemical analysis showing elevated levels of hepatic triglycerides in conjunction with a profound decrease in the methylation potential (i.e., reduced S-adenosylmethionine (SAM): S-adenosylhomocysteine (SAH) ratio), which was mainly driven by a six- to sevenfold increase in SAH levels. BHMT LKO mice also exhibited increased lipid peroxidation and lysosomal dysfunction compared to floxed mice. Early signs of inflammation were seen in the livers of BHMT LKO mice of both sexes, as evident from significant increase in CD68-positive cells and interleukin 1β levels. Additionally, there was a moderate increase in fibrosis, as evidenced by the upregulated expression of α-smooth muscle actin and collagen II levels and the histological assessment of picrosirius red-stained liver sections of BHMT LKO mice of both sexes compared to their respective counterparts. These findings demonstrate that hepatic BHMT deficiency promotes lipid accumulation, lysosomal/proteasomal dysfunction, and early inflammatory and fibrotic changes in the liver by reducing the methylation potential. Collectively, our results underscore BHMT as a critical regulator of liver homeostasis and a potential therapeutic target in liver-related disorders. Full article

Introduction: Pathogenic mutations in leucine-rich repeat protein kinase-2 (LRRK2), particularly G2019S, constitute the most common cause of autosomal dominant PD. Methods: Mouse models encoding human mutant alpha-synuclein (SNCA A53T) and LRRK2 G2019S were treated with a brain-penetrant kinase inhibitor (BK40196). Behavior, nigrostriatal and mesolimbic dopamine (DA) pathways were examined. Results: Mice harboring LRRK2 G2019S do not show age-dependent motor symptoms, but mice encoding SNCA A53T display motor deficits, while both strains exhibit anxiety-like behavior and BK40196 improves motor and behavioral defects. BK40196, a multi-kinase inhibitor of Abelson (Abl), Discoidin domain receptor (DDR)-1, c-KIT and FYN, alters microglial morphology and alpha-synuclein levels in SNCA A53T mice and improves DA neurotransmission, primarily via the nigrostriatal system. BK40196 inhibits brain LRRK2 G2019S (IC₅₀ of 89nM) and does not affect phosphorylated or total peripheral LRRK2 levels (lungs, kidneys, liver, etc.). LRRK2 G2019S mice treated with BK40196 exhibit distinct increases in DA in mesolimbic neurons such as the nucleus accumbens (NAcc), suggesting differential mechanisms of DA neurotransmission in mutant alpha-synuclein and LRRK2 models of PD. Conclusions: LRRK2 G2019S may primarily involve mesolimbic pathways leading to nonmotor symptoms independent of the motor and behavioral manifestations associated with alpha-synuclein via the nigrostriatal system. BK40196 may provide a comprehensive and synergistic therapeutic approach that addresses multiple mechanisms to reduce the pathologies related to LRRK2 G2019S and/or SNCA in PD. The multiple pathologies of PD necessitate a holistic approach that simultaneously targets inflammation and autophagy and LRRK2 inhibition. Full article

The use of postmortem (autopsy) material in fundamental and applied biomedical research significantly facilitates the collection of biomaterial for statistically robust sample cohorts. However, natural adaptive processes to developing cellular stress in the early postmortem period, caused by oxygen and nutrient deprivation, trigger the activation of numerous genes promoting cell survival under stress. Many of these activated pathways are also crucial for tumor cell survival in vivo, as evidenced by various transcriptomic studies. This study aimed to investigate the potential influence of postmortem interval (PMI) duration on gene expression in normal and tumor tissues. Using a model of chemically induced hepatocellular carcinoma in mouse liver, we comparatively analyzed the dynamics of transcript levels for several genes (BRCA1, BRCA2, CHEK1, CHEK2, ATM, CDK12) in paired samples of normal and tumor tissue over a 24-h PMI using RT-qPCR. In normal tissue, gene expression increased significantly, while tumor tissue demonstrated relative transcriptional stability, with no substantial changes in the studied transcript levels. A critical finding was the observed convergence of expression profiles: initial differences between the tissues were completely eliminated by 24 h PMI. This pattern developed despite formally adequate RNA quality (RQN) and the absence of clear signs of progressive autolysis in histology, indicating the insufficiency of standard quality criteria for detecting postmortem changes. These findings collectively underscore the critical importance of minimizing and controlling PMI during the biobanking of oncological samples for reliable transcriptomic research. Full article

Acute liver failure is often accompanied by neurological disturbances collectively referred to as hepatic encephalopathy (HE), characterized by neuroinflammation and subsequent cognitive decline. Insulin-like growth factor 1 (IGF1) is a neuroprotective peptide with anti-inflammatory properties in the brain. The role of IGF1 in cognitive deficits and neuroinflammation during HE remains largely unexplored. In C57Bl/6 mice, HE was established through an intraperitoneal injection of azoxymethane (AOM), and tissues were collected at defined time points during disease development. IGF1 expression in the cortex was downregulated following AOM administration. Central infusion of recombinant mouse IGF1 (rmIGF1) before AOM injection resulted in delayed neurological impairment, reduced microglial activation, and decreased proinflammatory cytokine and chemokine production in AOM mice. In vitro, rmIGF1 and conditioned media derived from rmIGF1-treated primary neurons attenuated phagocytic activity and C–C motif chemokine ligand 2 (CCL2) production in the microglial cell line EOC-20. Collectively, our results show that IGF1, whose levels decline during HE, alleviates neuroinflammation and improves the pathological state of AOM-treated mice through the suppression of microglial activation and the regulation of neuron–microglia paracrine communication. Full article

Metabolic dysfunction-associated (non-alcoholic) steatotic liver disease (MASLD) is a chronic inflammatory liver disorder characterized by excessive hepatic lipid accumulation. Its progressive subtype, metabolic dysfunction-associated (non-alcoholic) steatohepatitis (MASH), is featured by enhanced inflammation and liver injury. Some MASH cases are accompanied by hepatic fibrosis, which may progress to cirrhosis and hepatocellular carcinoma (HCC). MASLD is also associated with comorbidities such as cardiovascular disease and chronic kidney disease. To date, only Resmetirom has been approved by the FDA for MASH treatment, highlighting the urgency of investigating MASH pathogenesis and developing effective therapeutic agents. Establishment of experimental animal models which can mimic the clinical symptom of MASLD are fundamental to explore therapeutic targets and advance clinical drugs development. Therefore, this review focus on the pathological features of MASLD/MASH and comprehensively summarizes the current MASH-related mouse models, which can be useful for researchers to select appropriate models in order to explore the underlying mechanisms and dig novel targets for MASH treatment. Full article

N⁶-methyladenosine (m⁶A) is the most common internal modification in eukaryotic mRNA, essential for post-transcriptional regulation. MeRIP-seq is widely used for m⁶A profiling, but RNA degradation challenges accurate analysis. While the effects of sample handling on RNA are known, the impact of tissue sample storage durations on m⁶A remains unclear. We investigated how sample storage durations (0, 2, 12, 24, and 48 h at room temperature) affect RNA integrity, m⁶A peaks, and transcriptomes in mouse liver. RNA integrity declined with time, reducing m⁶A peak number and reproducibility. Prolonged storage diverged m⁶A profiles, increased unreported peaks, shifted RRACH motifs, and redistributed peaks to intergenic/intronic regions. Integrated data showed opposing changes in m⁶A and expression for some genes, suggesting storage degradation confounds epitranscriptomic interpretation. Sample storage durations are critical for m⁶A accuracy, emphasizing the need for standardized handling in MeRIP-seq studies. Full article

Background/Objectives: Impairment in pulsatile insulin release contributes to insulin resistance and is one of the earliest markers of developing type 2 diabetes. Insulin delivered to the liver in pulses has a stronger glucose-lowering effect than continuous insulin delivery. Whether pulsatility benefits the islet itself is an open question. We previously showed that reducing glucokinase activity with the glucokinase inhibitor D-mannoheptulose (MH) improves function in islets exposed to prolonged hyperglycemic conditions. In this study, we test whether pulsatile vs. continuous delivery impacts the effectiveness of MH in islets. Methods: Islets were exposed to high-glucose conditions (20 mM glucose) for 24 or 48 h to induce early adaptations to hyperglycemia. We then used a specially designed perifusion system to impose pulsatile activity by exposing mouse islets to 3 min of MH in 20 mM glucose and 3 min of only high levels of glucose. Islets given intermittent MH for 18 h were compared with continuous delivery of MH at a full (2.5 mM) or half (1.25 mM) dose. Results: MH delivered by the forced oscillatory system reversed the effects of hyperglycemia and restored glucose sensing more effectively than continuous delivery. Specifically, fura-2AM imaging of intracellular calcium showed that islets given pulsatile MH had greater reductions in the elevated basal calcium caused by hyperglycemic conditions, improved the glucose stimulation index, and improved phase 0 response (indicating glucose-stimulated calcium uptake by the endoplasmic reticulum). Conclusions: These findings suggest that the loss of oscillatory glucose metabolism in islets contributes directly to beta-cell dysfunction. Full article

Skeletal muscle development and physiological homeostasis are profoundly influenced by environmental cues. Among these factors, ambient temperature represents a critical determinant of growth performance and metabolic adaptation in mammals. However, the effects of different ambient temperature ranges on skeletal muscle characteristics and on responses across multiple visceral tissues remain poorly understood. In this study, five ambient temperature conditions (16 °C, 20 °C, 24 °C, 28 °C, and 32 °C) were established to investigate their physiological impacts in a mouse model. Our results demonstrate that ambient temperature markedly influences growth performance and skeletal muscle phenotype. Notably, mice housed at 20 °C showed relatively preserved grip strength and a shift in myofiber cross-sectional area distribution, although these findings did not consistently indicate superior skeletal muscle development across all indices. Further analysis revealed that ambient temperature significantly modulated the expression profiles of myosin heavy chain (MyHC) isoforms in skeletal muscle. Specifically, cold exposure was associated with an upregulation of the slow-twitch-related MyHC I, whereas heat stress correlated with an elevation of the fast-twitch-related MyHC IIb. Functional assessments indicated that exposure to colder or hotter conditions was associated with impaired muscle performance, as reflected by reduced grip strength at 16 °C, 28 °C, and 32 °C, and decreased endurance capacity at 28 °C and 32 °C. Histological analyses of major visceral organs revealed no obvious structural alterations in the heart, liver, spleen, lung, or kidney across temperature conditions. However, exposure to thermal extremes (16 °C and 32 °C) significantly reduced intestinal villus height, suggesting compromised intestinal integrity under temperature stress. Collectively, these findings indicate that ambient temperature is associated with multi-tissue changes in skeletal muscle characteristics, functional performance, and intestinal morphology. This study provides new insights into how environmental temperature modulates tissue adaptation and physiological homeostasis in mammals. Full article

In this study, the pharmacokinetic (PK) characteristics of oleuropein present in the olive tree (Olea europaea) were determined. We developed and validated a highly sensitive ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method to quantify oleuropein and its aglycone derivative, thereby establishing their pharmacokinetic properties in vitro and in vivo. Quantification of oleuropein and oleuropein aglycone was performed using selected reaction monitoring (SRM) with heated electrospray ionization in negative ion mode, employing mass transitions of m/z 275.06 and 307.137 for the respective analytes, and methylparaben as the internal standard. The calibration curve for both exhibited a range from 1 ng/mL to 1000 ng/mL, utilizing a total of 10 calibrator standards. The method demonstrated superior sensitivity, precision, and reproducibility, facilitating accurate quantification of analytes over a wide concentration range in biological matrices. To develop a pharmacokinetic profile, C57BL/6 male mice were administered oleuropein at a dose of 100 mg/kg body weight via oral gavage, and plasma levels were examined by LC-MS/MS. Oleuropein pharmacokinetics were evaluated exclusively, as plasma levels of oleuropein aglycone remained below the limit of quantification throughout the 24 h sampling period. Mass analysis of plasma samples identified multiple glucuronidated and sulfated metabolites, establishing Phase II metabolism as the dominant pathway governing the systemic disposition of oleuropein. In addition, the metabolic stability of the compounds was also investigated in mouse liver microsomes and S9 fractions to define the in vivo stability of oleuropein and oleuropein aglycone. Full article